Dunisławska A. et.al.

Development and application of genome sequencing in studies ...

The chicken is the first non-mammalian amniote whose genome was sequenced. The sequencing was carried out by the International Chicken Genome Sequencing Consortium and it was aimed at deciphering the genetic code of Red Jungle Fowl (Gallus gallus) and to compare it with known mammalian genomes, including the human genome (18). An individual, inbred female was chosen for sequencing, to reduce the heterozygosity and cover both chicken sex chromosomes (W and Z). The results of this project have created new possibilities for the analysis of the chicken genome. Conducted analyses showed that the total length of the sequence of the chicken genome is more than a billion nucleotides that encode about 15 500 genes (number of genes verified by Ensembl) (28). It was found that the chicken genome has a relatively low content of repetitive sequences (11%) compared to mammals, which typically contain 40–50% of repetitive sequences in their genome (8). The low level of repetitive sequences results from the decreased overall size of the Avian genome in comparison to mammalian genomes, e.g. size of the chicken genome is ~1.05 Gbp, whereas size of the human genome is ~2.8 Gbp. This characteristic of the chicken genome allowed for a relatively easy assembly of the entire DNA sequence and reduced the risk of errors (35). Comparative analysis of the DNA sequences of three chicken breeds (a broiler, a layer and a fancy breed – Silkie) revealed the presence of approx. 2.8 million single nucleotide polymorphisms (SNPs) (36). The comparison between the three genomes: human (mammal), chicken (bird), and fugu (fish) showed that about one third of all genes are common to all three species. Those genes have been considered a common characteristic of vertebrates in general (8). During the evolution of the Aves, a number of gene families were lost from the genome, responsible for traits such as: vomeronasal receptors, casein milk proteins, proteins present in saliva and enamel proteins. On the other hand, new genes were gained, responsible for: scales, claws and feathers and genes encoding proteins specific to the eggshell (e.g., ovocleidin 116) (18). As a consequence, the chicken has become a model bird organism, with the genome sequence available, as well as ease at obtaining biological material resulting from a high reproduction rate and early sexual maturation of the individuals ... [full text in English...]

Babicz M. et.al.

Sexual activity of different gilt genotype groups of the Pulawska ...

One of the conditions of high efficiency in pig production is successful reproduction. The use of high meatiness gilts and sows in mass breeding often causes a lack of or low intensity of typical sexual behaviour in heat which has a negative influence on the reproduction rate (7). Mating behaviour in pigs is observed for a short period of time and occurs at the moment of contact of a boar and a sow in heat. The sow plays a prominent role, sending signals toward the boar. During mating the boar sniffs the sow, directs his nose at her body, moves its snout along the sides and close to the vulva, producing a series of throaty grunts being a component part of courtship. The increasing tactile stimulation of the sow also heightens the sexual arousal of the boar (4). The moment at which the sow exhibits full tolerance to the boar (the so called lordosis reflex) shows the peak of the heat period and the optimal time for mating or insemination. The appropriate identification of oestrus symptoms in sows is hindered by the so called ‘silent heats’. Their occurrence is initiated, among other things, by stress stimuli which may provoke masking of sexual behaviours (1, 2, 7). Current research indicates that the intensity of sexual behaviour (8) as well as the age at which females show external manifestations of sexual activity (9) is conditioned genetically. Identifying the association between DNA polymorphism and sexual activity of gilts could be one of the ways of limiting problems related to reproduction. The aim of the study was to analyze sexual activities of gilts representing various genotype groups in the RBP4 and MC4R locus. Material and methods Animals. Research was conducted on 72 gilts of the Pulawska breed (conservation breeding). All animals were subject to veterinary prevention, husbandry conditions adhered to animal welfare standards, feeding was adjusted to the age and the physiological condition of the animals according to animal feeding standards (6). Sexual activity observations were carried out in the course of the first and the second heats. The activity during oestrus was evaluated on the basis of the intensity of heat symptoms and the duration of the lordosis reflex (Tab.2). The observation of gilts behaviour was carried out twice a day: in the morning and in the afternoon (the results are shown in tables as average of both observations. The observations were performed by trained employees of the pig farm). The starting point for the proper measuring period was defined as the manifestation of the first signs of oestrus, i.e. restless behaviour, swelling of the vulva, jumping onto other females, reaction to the testing-boar. In order to establish the precise moment when the oestrus begins control observations were performed 1 day before the predicted oestrus based on the calendar. During the observation all the gilts were marked in a visible place on their backs in a manner enabling easy identification. Detected polymorphism. Synonymous substitution (c.156C>T, p.(=)) of the RBP4 (SNP: rs55618789) and nonsynonymous substitution (c.1426A>G, p.Asp298Asn) of the MC4R (SNP: rs81219178) were identified using the HinfI and TaqI enzymes, respectively (Tab.3). A and G alleles as well as AA, AG and GG genotypes (MC4R locus) and C and T alleles as well as CC and CT genotypes (RBP4 locus) were identified in the examined population of gilts. ... [full text in English...]

races of animals

Kowalska D., et al.

European badger

The European badger (Meles meles) is the largest member of the mustelid family (Mustelidae) found in Poland. It lives almost all over Eurasia, except northern areas of the former Soviet Union and the Scandinavian countries. The European badger most often inhabits densely wooded areas. It feeds on both animal and plant foods, and is classified as a carnivore. Badger skins are not fully used in the fur industry They are usually used for production of skin rugs and accessories, such as hunting bags.[full text in Polish]